I didn't come up with this, it's part Chuck Klosterman's 23 Questions. They are fun to ask people though.

Your best friend is taking a nap on the floor of your living room. Suddenly, you are faced with a bizarre existential problem:

This friend is going to die unless you kick them (as hard as you can) in the rib cage. If you dont kick them while they slumber, they will never wake up. However, you can never explain this to your friend; if you later inform them that you did this to save their life, they will also die from that. So you have to kick a sleeping friend in the ribs, and you cant tell them why. Since you cannot tell your friend the truth, what excuse will you fabricate to explain this (seemingly inexplicable) attack?